Electronic device packages such as BGA (Ball Grid Array) semiconductor packages are well known. Such a BGA semiconductor package has a package board, for example, made of ceramic. An electronic device such as an LSI chip is mounted on the package board. The BGA semiconductor package is mounted on a printed wiring board, for example, made of resin. A solder material such as BGA balls (or solder balls) is used for mounting the BGA semiconductor package on the printed wiring board. The respective BGA balls are joined to conductor pads on the package board side and conductor pads on the printed wiring board.
[Patent Document 1] Japanese Laid-open Patent Publication No. 2001-110940
[Patent Document 2] Japanese Laid-open Patent Publication No. 2006-24889
[Patent Document 3] International Publication Pamphlet WO 99/36957